Secondary air intake for gas burners



D .L A w N O H c S ug.. L, 1939.

SECONDARY AIR INTAKE FOR GAS BUBNERS Filed April l, 1&5@

Patented Aug. 1, 1939 UNITED STATES PATENT GFFICE SECONDARY AIR. INTAKE FR GAS BURNERS William Schonwald, Chicago, ll., assigner to Middleby-Marshall Oven Co., Chicago, Ill., a

corporation of Illinois This invention relates to improvements in secondary air intakes for gas burners designed particularly for use in conjunction with bake ovens.

One object of the invention is to provide a heating unit for use inv conjunction with bake .ovens or other relatively closed chambers comprising one er more elongated burners Yprovided with means for supplying secondary air to said burner or burners throughout the length of the latter.

Another object of the invention is to provide `an air intake structure for burners which enables the flow of the secondary air to the burner to be controlled for obtaining most effective combustion of the fuel within the oven.

Other objects of the invention' relate to various features of construction and arrangement of parts which will be apparent from a consideration of the following specification and accompanying drawing wherein:

Fig. l is a perspective View of dual burners illustrating secondary air intake members associated therewith, the figure illustrating the heating unit disposed on the floor of an oven, one wall of which is fragmentarilyv illustrated;

Fig. 2 is a sectional View taken on 1in`e2--2 of Fig. 1

Fig. 3 is a broken top plan view of the heating unit including a pair of burners and the secondary air intake members therefor; and

Fig. 4 is a sectional view corresponding to Fig. '2 showing the secondary air intake in association Vwith a single burner.

In the drawing, Ill indicates a wall of a relatively closed heating chamber such as a bake oven comprising a rotary reel carrying a plurality of trays (not shown), that is, a tray-type oven. Where such ovens are heated by gas, the burners are disposed generally on or adjacent the iloor Il thereof. In Figs. 1, 2 and 3, a heating unit comprising two burners I2 and I3 is illustrated These burners comprise pipes of suitable diameter which are capped at their inner ends I4 and communicate with a gas supply pipe or manifold I5 which may be provided with either automatic or manual gas regulating means such as indicated at I6. The Iburners I2 and I3 preferably are provided with two rows of gas outlet openings or ports I'I as shown in Figs. 2 and 3 through which the gas issues.

Primary air for admixture to the gas is admitted to the pipes by conventional means (not shown) but it has been found desirable to augment the air supply tothe burners where such burners are used ior heating an enclosed charnber such as an oven of the type referred to. The secondary air intake means illustrated may be formed of sheet metal and as shown in Fig. 2, comprises a member i8 shaped to form longitudinal passages I9, and 2i which are coeXtensive with the length oi the burners. These passages I9, 2U and 2| are shown as being rectangular in cross section. The forward end of said member I8 extendsoutwardly of the oven wall I0 and is open to the atmosphere.

Cooperating with the rectangular-shaped ducts I9, 2E] and 2| are members 22, 23 and 24, respectively. These members likewise may be formed of sheet metaland are arranged to lit the side walls of the corresponding ducts` I9, 20 and 2| telescopically and to form above the hori- Zontal walls of said ducts longitudinal passages 25, 26 and 2l which are co-extensive with the inner. portions of the burners I2 and i3 which are provided with the gas 'outlet ports il. The members 22, 23 and 24 are of such Vertical height that their top walls are substantially `flush with the upper surfaces ofthe burners I2 and I3. These members 22, 23` and 24 havetheir side walls adjacent the respective burners inclined Vas shown at 22a, 23a and 24a into `rather close proximity to the peripheral surfaces of the burners l2 and I3 as shown clearlyin1l1"ig.l2.V

The inclined wall sections 22a, 23a and 24a are provided with air outlet ports 22h, 23h and 24h, respectively, for discharging secondary air to the burners for supplying adequate oxygen to the flames thereof or for admixtur-e with the gas issuing from the ports I'I. The air thus supplied enters the apparatus through the open ends of the ducts I9, 2i), and 2| which, as stated, are disposed exteriorly of the furnace. The air flows through the ducts mentioned and passes upwardly through ports I9a, 20a and 2Ia into the ducts 22, 23 and 24, respectively, whence the air flows through the above mentioned ports or orifices 22h, 23h and 24h to the burners.

This arrangement supplies secondary air to the burners in adequate quantities to insure complete cornbustion of the gases issuing from the burners within the oven.

As shown in Fig. 1, the forward ends of the secondary air passages are capped or closed as at 28. The spacing of the apertures ISa, 20a and 2Ia are such as to effect suitable distribution of the air throughout the ducts 25, 26 and 2l while the spacing of the orifices 22h, 23h and 2Gb preferably corresponds with the spacing of the gas outlet ports I'I of the respective burners as shown in Fig. 3.

Cil

In Figs. 1 and 2, the structure is shown as being provided with a sheet metal base 29. The parts of the unit may be spot Welded or otherwise suitably secured together as desired. At the exterior or intake ends of the passages or ducts I9 and 2l, suitable air regulating means may be provided for controlling the quantity of air admitted to the burners. Such means in the form illustrated comprise slidable gates 30 which may be adjusted vertically for controlling the intake of secondary air. The use of such gate on the intermediate duct 20 has been found unnecessary due to the fact that such duct supplies air to the adjacent rows of gas ports l1 of each of the lburners I2 and I3 although such regulating means may be employed if desired.

The burner unit as illustrated and described has been found not only to be of economical construction but to be capable of supplying secondary air to the burners throughout the length of said burners and thereby provide a more efcient and economical source of heat for bakers ovens. Its use is, of course, not limited to that mentioned. The flow of the vgas upwardly through the outlet ports l1 induces a ow of air through the adjacent openings 22h, 23h and 24h and effects the flow of air through the respective ducts I9, 20 and 2l as described.

In Fig. 4, a secondary air intake device for use with a single burner is illustrated. The burner is indicated by numeral 3| and the air intake ducts 32 and 33 are formed by the proper shaping of a sheet metal member 34. The telescopic members 35 correspond to members 22 and 24 of the above described modification and are provided with similar outlet air passages 35a for supplying air directly to the flames of the burner 35 for effecting a more complete combustion of the fuel and a more satisfactory and efcient heating unit.

While I have shown and described an embodiment of my improvement for the purpose of illustration, I do not wish to be'restricted specifically thereto since the principles, of the invention may be embodied in structures varying in details from those herein disclosed.

What I claim as new and desire to cover by Letters Patent is:

1. Secondary air supplying means for an elongated gas burner provided with longitudinally spaced gas ports comprising a sheet metal casing provided with two air duct-forming portions each extending along one side of said burner and having air intake openingsat the ends thereof and air outlet passages in an upper wall thereof, and additional duct-forming members each co-extensive with the ported portion of said burner and communicating with one of said other duct portions by means of said air passages in the latter, each of said additional duct-forming members having walls disposed adjacent the ported portions of the burner and provided with air outlet passages for distributing air to the burners throughout the length of the ported portions thereof. A

2. Secondary air supplying means for an elongated gas burner provided with longitudinally spaced gas outlet ports comprising a sheet metal member providing a pair of air supply ducts extending parallel with said burner on opposed sides thereof, said ducts having air distributing orifices spaced longitudinally thereof, and a pair of casing sections each arranged for communication with one of said ducts for receiving air through the respective orifices thereof and provided with an inclined apertured Wall disposed adjacent the gas ports of said burner for supplying air to the burner.

3. A secondary air supply structure for an elongated gas burner comprising a base disposed beneath the burner` and provided with upwardly extending side flanges, an air intake member seated on said base between said flanges provided with a pair of inverted channel portions one disposed at each side of said burner and having air ports in its upper wall and air intake openings at one end thereof, and air distributing means comprising inverted channel members embracing the side walls of said channel portions of said air intake member and provided with upper walls spaced above the upper ported walls of said channel portions to provide longitudinal air ducts therebetween and each having ports in a side wall thereof adjacent said burner for supplying air to the latter,

WILLIAM SCHONWALD. 

